This invention is concerned with safety device for the heat-emitting surface system coated with conductive paint such as carbon paint to prevent some accidents caused especially by wire disconnection of electrodes. Recently the heat-emitting surface system made out of conductive, thinly stretched sheet material such as conductive carbon paint has been used as means of electrically heating articles such as electric carpet and electric matting. Electrodes placed along edges of sheet surface supply power to thin flexible electrically conductive heat emitting material.
This type of heat-emitting surface ought to be as thin as possible and at the same time to be flexible in order to be handled easily. Flexibility and lightness are particularly important when the articles are merchandised as electric heating spreads or electric blankets. To meet the specifications lead wires and electrodes have taken the structure of a few thin wires laid side by side so as to reduce bulkiness of electrodes.